Field of the Invention
The invention relates to a projection screen, and particularly relates to a touch projection screen and a projection system including a projection device and the touch projection screen.
Description of Related Art
As electronic devices are developed to become multi-functional, the conventional click-button operational interface is no longer able to meet the user's needs. Under such circumstance, the development of the touch technology becomes more and more prosperous. Compared with the conventional click-button operational interface, inputting using a touch operational interface is more convenient and intuitive. The user may input by touching on a display surface of an electronic device by using a finger or a touch pen. In addition to the display surface of an electronic device, the touch technology may also be used in a projection screen for a projection device to project an image, so that the user may also input by touching the projection screen.
Currently, the capacitive touch technology is the main stream for the touch operational interface. The touch layer thereof is normally formed of a substrate and an indium tin oxide (ITO) electrode on the substrate. Due to limitations on the manufacturing technology, the touch layer including the ITO electrode is not applicable to a touch interface in a larger size. In addition, the touch layer used in the display surface of an electronic device requires a high light transmittance to prevent a negative influence on the display quality of the electronic device. Such requirement also increases the manufacturing complexity of the touch layer. Besides, to increase a touch area of the touch layer, electrode lines of the electrode in some designs are expanded by being formed with a plurality of rhombic electrodes connected to each other. However, such designs significantly increase the time required for an etching process of the electrode and make the manufacturing cost higher. Furthermore, the conventional touch operational interface is formed by one touch layer and is unable to flexibly cope with the practical needs by disposing a plurality of touch layers with respect to each other.
The information disclosed in this “BACKGROUND” section only serves to enhance understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Furthermore, the information disclosed in this “BACKGROUND” section does not mean that one or more problems to be solved by one or more embodiments of the invention were acknowledged by a person of ordinary skill in the art.